Having recently attended the ISOO’s CUI Fundamentals of Marking course, I would recommend data owners, compliance officers, and others follow the CUI Program Blog and look for future Marking courses. Feel free to reach out additional guidance.


  • No requirement to retroactively mark existing information
  • Expectation that any information shared must be marked going forward
  • When marking documents, all sheets must be marked; however cover sheets can be used in lieu of marking every page

CUI Resources